3d embossing

ABSTRACT

An embossing roll for producing fibrous products, has a structurized embossing surface suitable to run against an anvil roll. The structurized embossing surface includes male protrusions or female depressions starting from a base circumferential surface of the roll. The embossing pattern is characterized by the following features:
         the base areas of selected male protrusions or female depressions in the base circumferential surface are different;   the heights or depths of selected male protrusions or selected female depressions in a radial direction of the roll and starting from the base circumferential surface are different; and   the angles between sidewall sections and the adjacent base circumferential surface of selected male protrusions and/or female depressions are different.

FIELD OF THE INVENTION

The invention relates to an embossing roll for producing fibrousproducts, especially tissue paper products, non-woven products or ahybrid thereof and preferably hygiene and cleaning products with thepre-characterizing features of claim 1. The invention also relates to adevice for producing such fibrous product, a method for producing amulti-ply fibrous product and a fibrous product.

BACKGROUND OF THE INVENTION AND PRIOR ART

Hygiene or wiping products primarily include all kinds of dry-crepedtissue paper, wet-creped paper, TAD-paper (Through Air Drying) andcellulose or pulp-wadding or all kinds of non-wovens, or combinations,laminates or mixtures thereof. Typical properties of these hygiene andwiping products include the reliability to absorb tensile stress energy,their drapability, good textile-like flexibility, properties which arefrequently referred to as bulk softness, a higher surface softness and ahigh specific volume with a perceptible thickness. A liquid absorbencyas high as possible and, depending on the application, a suitable wetand dry strength as well as an appealable visual appearance of the outerproduct's surface are desired. These properties, among others, allowthese hygiene and wiping products to be used, for example, as cleaningwipes such as paper or non-woven wipes, windscreen cleaning wipes,industrial wipes, kitchen paper or the like; as sanitary products suchas for example bathroom tissue, paper or non-woven handkerchiefs,household towels, towels and the like; as cosmetic wipes such as forexample facials and as serviettes or napkins, just to mention some ofthe products that can be used. Furthermore, the hygiene and wipingproducts can be dry, moist, wet, printed or pretreated in any manner. Inaddition, the hygiene and wiping products may be folded, interleaved orindividually placed, stacked or rolled, connected or not, in anysuitable manner.

Due to the above description, the products can be used for personal andhousehold use as well as commercial and industrial use. They are adaptedto absorb fluids, remove dust, for decorative purposes, for wrapping oreven just as supporting material, as is common for example in medicalpractices or in hospitals.

If tissue paper is to be made out of pulp, the process essentiallycomprises a forming that includes a box and a forming wire portion, anda drying portion (either through air drying or conventional drying on ayankee cylinder). The production process also usually includes the crepeprocess essential for tissues and, finally, typically a monitoring andwinding area.

Paper can be formed by placing the fibers, in an oriented or randommanner, on one or between two continuously revolving wires of a papermaking machine while simultaneously removing the main quantity of waterof dilution until dry-solids contents of usually between 12 and 35% areobtained.

Drying the formed primary fibrous web occurs in one or more steps bymechanical and thermal means until a final dry-solids content of usuallyabout 93 to 97% has been reached. In case of tissue making, this stageis followed by the crepe process which crucially influences theproperties of the finished tissue product in conventional processes. Theconventional dry crepe process involves creping on a usually 4.0 to 6.5m diameter drying cylinder, the so-called yankee cylinder, by means of acrepe doctor with the aforementioned final dry-solids content of the rawtissue paper. Wet creping can be used as well, if lower demands are madeof the tissue quality. The creped, finally dry raw tissue paper, theso-called base tissue, is then available for further processing into thepaper product for a tissue paper product.

Instead of the conventional tissue making process described above, theuse of a modified technique is possible in which an improvement inspecific volume is achieved by a special kind of drying which leads toan improvement in the bulk softness of the tissue paper. This process,which exists in a variety of subtypes, is termed the TAD (Through AirDrying) technique. It is characterized by the fact that the “primary”fibrous web that leaves the forming and sheet making stage is pre-driedto a dry-solids content of about 80% before final contact drying on theyankee cylinder by blowing hot air through the fibrous web. The fibrousweb is supported by an air-permeable wire or belt or TAD-fabric andduring its transport is guided over the surface of an air-permeablerotating cylinder drum, the so-called TAD-cylinder. Structuring thesupporting wire or belt makes it possible to produce any pattern ofcompressed zones broken up by deformation in the moist state, also namedmoulding, resulting in increased mean specific volumes and consequentlyleading to an increase of bulk softness without decisively decreasingthe strength of the fibrous web.

To produce multi-ply tissue paper products, such as handkerchiefs,bathroom paper, towels or household towels, an intermediate step oftenoccurs with so-called doubling in which the base tissue in the desirednumber of plies of a finished product is usually gathered on a commonmulti-ply mother reel.

The processing step from the base tissue that has already beenoptionally wound up in several plies to the finished tissue productoccurs in processing machines (converting machines) which includeoperations such as unwinding the base tissue, repeated smoothing of thetissue, printing embossing, to an extent combined with full area and/orlocal application of adhesive to produce ply adhesion of the individualplies to be combined together as well as longitudinal cut, folding,cross cut, placement and bringing together a plurality of individualtissues and their packaging as well as bringing them together to formlarger surrounding packaging or bundles. Such processing steps may alsoinclude application of substances like scents, lotions, softeners orother chemical additives. The individual paper ply webs can also bepre-embossed and then combined in a roll gap according to the embossingmethods known in the art. Any embossing can lead to embossed elementsall having the same height or to embossing elements having differentheights. Plybonding, e.g. by mechanical or by chemical means are otherwell-known methods mainly used for hankies, napkins and bathroomtissues.

A well-known technique to increase the thickness of a paper product isto emboss the paper web. An embossing process is carried out in the nipbetween an embossing roll and an anvil roll. The embossing roll can haveprotrusions on its circumferential surface leading to so-called embosseddepressions in the paper web or it can have depressions in itscircumferential surface leading to so-called embossed protrusions in thepaper web.

Anvil rolls may be softer than the corresponding embossing roll and mayconsist of rubber, such as natural rubber, or plastic materials, paperor steel.

For manufacturing multi-ply tissue products, especially bathroom tissueand household tissue, three manufacturing methods for embossing andadhesively bonding of the plies have established. These are GoffraIncolla/spot embossing, DESL (Double Embossing SingleLamination)/Nested, and Pin-to-Pin/Foot-to-Foot.

In the first mentioned manufacturing method, Goffra Incolla, a first webis directed through the nip between an embossing roll and an anvil roll.In this nip the web is provided with an embossing pattern. Thereafter,an application roll for adhesive applies adhesive to those parts of thefirst web at which there are protruding embossing elements in theembossing roll. The adhesive is transported from an adhesive bath via anadhesive transfer roll to the application roll. A second web istransported to the first web and adhesively bonded to the first web inthe nip between the so-called marrying roll and the embossing roll. Theadhesive bonding takes place at those portions at which the adhesive wasapplied.

The second manufacturing method (DESL/Nested) is very similar to theabove-described Goffra Incolla method. It comprises an additional pairof rolls consisting of a second embossing roll and a second anvil roll.The additional pair of rolls serves to emboss the second web before itis adhesively bonded to the first web using the marrying roll.Typically, the additional pair of rolls is placed close to the firstpair of rolls and the marrying roll. Especially when using the so-calledNested-method such close arrangement is important. The Nested-method canbe considered as a special case of the general DESL-manufacturingmethod. For the Nested-method the embossing elements of the firstembossing roll and the embossing elements of the second embossing rollare arranged such that the embossed elements of the first embossed plyand the embossed elements of the second embossed ply fit into each othersimilar to a gearing system. This serves to achieve a mutualstabilization of the two plies. However, for the DESL manufacturingmethod such correlation between the embossed elements of the first,upper ply and the second, lower ply, does not have to apply.Nevertheless, in a literature the term DESL is often used synonymous toa Nested-method.

The third manufacturing method (Pin-to-Pin/Foot-to-Foot) is similar tothe DESL method. By means of two pairs of rolls both the upper ply andthe lower ply are embossed, respectively. Adhesive is applied onto theembossed protrusions of the first ply. The ply bonding however, is notachieved by means of a marrying roll as in the DESL method but isachieved directly by means of the protruding embossing elements of thesecond embossing roll. In order to achieve this, an exact adjustment ofthe width of the nip between the first embossing roll and the secondembossing roll is required, which is mainly defined by the individualthickness of both webs (upper ply and lower ply). Further, the embossingrolls have to be designed such that the protruding embossing elements ofboth rolls face each other. This is the reason why the terminologyPin-to-Pin or Foot-to-Foot embossing is used.

All above described methods have the following common features: thefirst embossing roll is formed of a hard material, usually metal,especially steel, but there are also known embossing rolls made of hardrubber or hard plastics materials. The embossing rolls can be a maleroll having individual protrusions. Alternatively, the embossing rollcan be a female roll with individual embossing depressions. Typicaldepths of the engraved embossing patterns are between 0.4 and 2.0 mm.

The anvil roll typically has a rubber coating with a hardness between 35Shore A and 85 Shore A. However, structurized anvil rolls, especiallyrolls made of paper, rubber or plastics materials or steel are alsoknown.

The applicator roll for adhesive is usually also a rubber roll with aplain smooth circumferential surface, wherein the hardness of the rubbercoating is between the hardness of the anvil roll and the hardness ofthe marrying roll. Commonly used values for the hardness of the rubbercoating are 70 to 85 Shore A. When selecting the rubber material itscompatibility with the adhesive to be applied has to be ensured.

The application system for adhesive consisting of applicator roll,adhesive transfer roll and adhesive bath can be designed as a so-calledimmersion roll system in which the adhesive transfer roll is immersedinto the adhesive bath and transports adhesive by means of surfacetension and adhesive forces out of the adhesive bath. By adjusting thegap between the adhesive transfer roll and the applicator or applicationroll, the amount of adhesive to be applied can be adjusted. Applicationrolls may be structured rolls. Recently, adhesive transfer rolls havebecome known having defined pit-shaped depressions in theircircumferential surface. Such adhesive transfer rolls are known asAnilox-rolls. Such roll is usually made of ceramic material or it is aroll made of steel or copper and coated with chromium. Excessiveadhesive is removed from the surface of the Anilox-roll by means of ablade. The amount of adhesive is determined by the volume and the numberof depressions. Alternative application systems for applying adhesivesare based on a spraying equipment (Weko-technique).

A second possibility to influence the amount of adhesive transferred isthe adjustment of the difference in circumferential speeds of theadhesive transfer roll and the applicator roll. Typically, the adhesivetransfer roll rotates slower than the applicator roll. Thecircumferential speed of the adhesive transfer roll is usually between5% and 100% of the first circumferential speed of the applicator roll.The adhesive bath can be designed as a simple trough, applicationsystems with a blade can also be designed as chamber systems.

The embossing technologies Goffra Incolla/spot embossing andDESL/Nested, both use an additional roll, the so-called marrying rollfor laminating together the plies. The marrying roll commonly has asmooth rubber surface with a hardness of about 90-95 Shore A. A suitablematerial is e.g. NBR (acrylnitrile-butadien rubber). However, marryingrolls also have become known which, in addition to the rubber coating,are provided with a steel coating. Such steel coating is often providedin form of a steel band spirally wound onto the rubber coating.

In case that the single layers individually or together arepre-embossed, a so-called micro-pre-embossing device is used. Suchpre-embossing device is often used in combination with the GoffraIncolla technology. Also commonly used is a printing onto the tissueproduct before or after the ply bonding step. Also known are variantsincluding the application of chemical substances, especially lotions andsofteners.

Another well-known embossing technique comprises a steel embossing rolland a corresponding anvil steel roll (so-called Union embossing). Thesurfaces of these rolls are being formed in such a manner thatdeformation of the paper and mechanical plybonding without usingadhesives are achieved within one single embossing step.

When using all of the above described three embossing methods it isadvantageous to provide a control for the tension of the web both beforeand after the ply bonding because the physical properties of the web andespecially the stress-strain characteristic can be changed significantlyin the embossing step.

FIG. 11 a depicts part of the circumferential surface of an embossingroll 100 having discrete protrusions 102 leading, when cooperating inthe above described way with a yieldable anvil roller, to a product asshown in FIG. 11 b. Such paper product 110 has a main portion lying in abase plane 112 from which embossing depressions 114 project. In theprior art example as shown in FIGS. 11 a, 11 b, the embossing roll hasmale embossing elements 102 all of which have the same height andgeometry. However, a so-called double height embossing is also known inthe prior art. To exemplify this, FIG. 12 a shows part of the outercircumferential surface of an embossing roller 120 with two differenttypes of male embossing protrusions. These are protrusions 122 having ahigher height as well as protrusions 124 with a smaller height.Otherwise, in the example according to FIG. 12 a, the protrusions have asimilar cross-sectional geometry. However, it is also known in the artto combine embossing protrusions of different geometry and differentheight together. Such an embossing technique is known from EP 0 797 705A1.

The resulting paper product 130 is schematically shown in FIG. 12 b.Starting from a base plane 132, the paper product has embossingdepressions 134 with a larger depth as well as embossing depressions 136being smaller in size.

The embossing rolls used in the prior art are mainly manufactured usingthe so-called moletage technique which is a roll engraving by means of acold forming of the steel of the embossing roll. According to suchmoletage technique, usually several cold forming steps and severaletching steps have to be carried out. This known production techniqueplaces some limitations on the shape of the protrusions in the surfaceof the roll. The slope angle has an impact on the mechanical stabilityof the paper product produced with such an embossing roll. If the slopeangle is smaller, the product has a smaller local stability around theembossed structure because locally the fiber structure is destroyed to alarger extent. Therefore, for reasons of a sufficient mechanicalstability of the paper product and of the constraint put upon themanufacture of protrusions on the surface of the roll using the moletagetechnique, a slope angle of at least 23° is commonly used in the art.

Another engraving technology for manufacturing embossing rolls for thetissue and hygiene industry is etching. Within a first step, a mask isapplied on the circumferential surface of the embossing roll followed bya second step in which the surface is etched by applying acid at thoseareas where no mask has been applied. The result is a circumferentialsurface of the roll which is partly engraved, wherein the transitionbetween engraved areas and non-engraved areas has a step angle of 0° upto 10°. In other words, the etching technique leads to a step-likesurface structure. The method steps of masking and etching with the sameor different geometries of masks can be repeated several times. By usinga repeated etching technique, a surface structure can be achieved whichis similar to discrete stairs which extend from the originalcircumferential surface of the roll into the material of the roll.

A further technique for manufacturing embossing rolls for the tissue andhygiene industry is CNC milling. This technique is often used forsimpler rectangular elements, for example truncated pyramids. The angleof the embossing elements and the radial direction of the embossing rollcan be easily varied in a wide range if such angle is the same for allembossing elements.

Another technique predominantly used for rolls made of plasticsmaterial, like rubber rolls, is the use of a laser ablation technique.Laser techniques are used for rolls made of plastic material as well asfor steel rolls. Other manufacturing methods for embossing rolls aremanually engraving techniques or galvanoforming. In principle acombination of such techniques can be used for manufacturing embossingrolls. One preferred manufacturing process is based on masking/etchingtechnology in combination with moletage. Another well-known combinationof engraving techniques is a multi-step etching technique with at leastfive, preferably around 10 separate etching steps, and the finalrounding of the resulting steps in order to achieve a smooth shape ofthe embossing elements produced. Useful rounding steps are brushing withmetal brushes, short overall etching or blast treatment with hardparticles, such as glass, sand or corundium.

The embossing not only serves to provide bulk to the fibrous product butalso to provide an improved optical appearance to the product. Theoptical appearance of a product is important for consumer products andalso serves to provide a higher degree of recognition to the product.The optical appearance can be improved by combining embossing andcoloring steps. Another reason for embossing is to generate higherabsorbency or improved perceived softness.

SUMMARY OF THE INVENTION

It is the object of the invention to provide an embossing roll, afibrous product, as well as a device and method comprising suchembossing roll for producing such fibrous product with a new embossingtechnology in order to increase the versatility of possible opticalappearances of the product.

This object is solved by an embossing roll with the features of claim 1,a method for producing a multi-ply fibrous product with the features ofclaim 19, a device for producing fibrous products with the features ofclaim 35 and a fibrous product according to claim 47. Preferredembodiments follow from the dependent claims.

According to the invention, an embossing roll for producing fibrousproducts, especially tissue paper products, non-woven products or ahybrid thereof, and preferably hygiene and cleaning products, comprisesa structurized embossing surface suitable to run against an anvil rollwherein the structurized embossing surface comprises male protrusions orfemale depressions starting from a base circumferential surface of theroll. The embossing pattern is characterized by the followingcharacteristics:

-   -   the base areas of selected male protrusions or female        depressions in the base surface are different;    -   the heights of selected male protrusions or the depths of        selected female depressions in a radial direction of the roll        and starting from the base circumferential surface are        different; and    -   the angles between side wall sections and the adjacent base        circumferential surface of selected male protrusions and/or        female depressions are different.

Male protrusions of the embossing roll translate into embosseddepressions in the product, like depressed dots, while femaledepressions in the roll lead to embossed protrusions in the fibrousproduct, especially cushion-like shapes. Ideally, the correlationbetween the inventive embossing roll and the fibrous product achievedfrom using such embossing roll in a device comprising such roll and acooperating anvil roll leads to a mirror image of the fibrous product ascompared to the inventive embossing roll. However, there is actually aloss which occurs in the production process. Such loss can be attributedto the fact that the fibrous product as processed is visco-elastic, i.e.during embossing, there is a certain part of the deformation which iselastic. Therefore, after the embossing step, there is some spring backbehaviour of the fibrous product so that the geometry of the embossingroll does not generate an embossed product which is the mirror image ofthe roll. The degree of loss depends on the material of the fibrousproduct, the characteristics of the embossing roll and anvil roll andmany other factors, but mainly depends on the geometry of the embossingpattern provided on the circumferential surface of the embossing roll.

The fibrous product according to the invention is especially a tissuepaper product, non-woven product or a hybrid thereof, and preferably ahygiene and cleaning product. It has at least one ply with an embossingpattern comprising embossed depressions, like depressed dots, orembossed protrusions, like cushion-like shapes, the embossed depressionsor embossed protrusions starting from a base plane of the ply. Theembossing pattern is characterized by the same basic characteristics ascan be found in the embossing roll, however, in the inverse pattern ofthe product and with the above-discussed loss:

-   -   the base areas of selected embossed elements, in particular        embossed depressions or embossed protrusions, in the base plane        are different;    -   the depths of selected embossed depressions or the heights of        selected embossed protrusions perpendicular to the base plane        are different; and    -   the angles between side wall sections and the adjacent base        plane of selected embossed depressions or embossed protrusions        are different.

The term non-woven according to ISO 9092, DIN EN 29092 is applied to awide range of products which, in terms of their properties are locatedbetween those of paper (DIN 6730, May 1996) and cardboard (DIN 6730) onthe one hand, and textiles on the other hand. As regards non-woven alarge number of extremely varied production processes are used, such asthe air-laid and spun-laced techniques as well as the wet-laidtechniques. The non-wovens include mats, non-woven fabrics and finishedproducts made thereof. Non-wovens may also be called textile-likecomposite materials, which represent flexible porous fabrics that arenot produced via the classic methods of weaving warp and weft or bylooping. In fact, non-wovens are produced by intertwining, cohesive oradhesive bonding of fibers, or a combination thereof. The non-wovenmaterial can be formed of natural fibers, such as cellulose or cottonfibers, but can also consist of synthetic fibers such as polyethylene(PE), polypropylene (PP), polyurethane (PU), polyester, fibers on thebasis of polyethylenterephtalate, polyvinyl alcohol, nylon orregenerated cellulose or a mix of different fibers. The fibers may, forexample, be present in the form of endless fibers or pre-fabricatedfibers of a finite length, as synthetic fibers, or in the form of staplefibers. The non-wovens as mentioned herein may thus consist of mixturesof synthetic and cellulose fibrous material, e.g. natural vegetablefibers (see ISO 9092, DIN EN 29092).

The term “hygiene products” and “cleaning products” as used hereincomprise bathroom tissue, household towels, handkerchiefs, facialtissues, napkins, wiping and cleaning products as well table ware. Itdoes not comprise wall paper products.

The fibrous product according to the invention is highly variable interms of the shape of the embossing pattern. The embossing pattern canbe both embossing protrusions or embossed depressions as explainedabove. The embossing pattern is a freely shaped 3-dimensional geometry.This means that there are no more standardized geometries of theembossed protrusions or depressions or, at least, there are no moregroups of embossed protrusions or embossed depressions all having thesame shape. This easy requirement that not all embossed depressions (incase of male embossing protrusions on the embossing roll) or embossedprotrusions (in case of female embossing depressions on the embossingroll) are the same, leads to the above listed characteristics of thepaper product.

Depending on whether the embossing roll has male protrusions or femaledepressions on its circumferential surface, a base plane comparable tothe base plane 112 and 132 in the prior art examples according to FIG.11 b and FIG. 12 b can be defined.

According to the invention, a freely designed three dimensional surfacestructure of the embossing roll translates into the claimed fibrousproduct. However, as outlined above all embossing processes have a loss,so that the embossed product does not assume the exact mirror image formof the embossing roll. This loss leads to angles in the embossedelements of the product which are not as steep as the correspondingangles on the embossing roll. This general observation is also valid forthe inventive 3-dimensional embossing which has to be accounted for whendesigning a suitable embossing roll to produce the inventive fibrousproduct. The deviation of the embossing pattern in the product relativeto embossing pattern in the roll depends on the material properties ofthe paper product, the hardness of the anvil roll cooperating with theembossing roll, the line pressure during the embossing process, and therelation of depths, widths or slope angles of a specific embossingelement.

The device for producing fibrous products with at least one ply,especially tissue paper products, non-woven products or a hybridthereof, and preferably hygiene and cleaning products, comprises aninventive embossing roll as well as a cooperating anvil roll. Thestructurized embossing roll has a three dimensional surface withembossing elements in form of male protrusions or female depressions,the angles and heights/depths of selected embossing elements beingdifferent. In other words, the inventive embossing roll is the core of adevice for producing fibrous products according to the invention.Reference to selected embossing elements serves to clearly state thatnot all embossing elements must have a different geometry. For practicalreasons, this is not possible because an embossing roll usually has arepeating pattern on its outer circumferential surface so that, at leastwithin each of the repeating design sections, corresponding embossingelements will be identical. However, it is also possible that within onesingle design pattern translating into one sheet of bathroom tissue orone sheet of household towel, a plurality of individual embossingelements might be identical in shape. Therefore, the above givenreference to selected embossing elements being different intends todefine that the inventive roll, the inventive product as well as theinventive device using such roll provide a wide variety of differentgeometries in terms of size, height/depth, slope angle and overall shapeof individual embossing elements.

The inventive method for producing a multi-ply fibrous product,especially tissue paper product, non-woven product or a hybrid thereofand preferably hygiene and cleaning product comprises the method stepsof embossing a top ply using an embossing roll according to theinvention, supplying at least one further ply, and bonding together thetop ply and the further ply in the nip between the embossing roll and amarrying roll or in the nip between the embossing roll and a secondembossing roll for embossing the further ply. Such method provides theinventive three dimensional fibrous product.

Preferably the embossing roll according to the invention ischaracterized by angles β₁, β₂ being defined as the crossing of theorthogonal of male protrusions or female depressions direction (O₁, O₂)starting from a selected position on the local surface of maleprotrusions or female depressions and the base circumferential surfacewhereby such angles β₁, β₂ should be either larger than 30°, preferablylarger than 50° or such angles β₁, β₂ should be smaller than 20°.

According to a preferred embodiment, the embossing roll is shaped suchthat the local surface of at least one female depression is curved suchthat two orthogonal directions starting from selected positions on thecurved local surface can be defined, the two orthogonal directionscrossing the base circumferential surface at angles β₁, β₂ satisfyingthe equation 30°<|β₁−β₂|90° and preferably 50°<|β₁−β₂|<90°.

Such an embossing roll provides a high range of possible surfacegeometries, including curved depressions. According to the prior art,standard embossing protrusions might also have very small roundedportions at their edges in the range of 0.1 mm. Such rounded portionsare not covered by the above feature according to which femaledepressions are curved. What is meant by this is a curved surface whichby far exceeds locally arranged rounded edges as known from embossingprotrusions in the prior art.

Preferably, the structurized embossing surface is a freely shapedthree-dimensional surface. What is meant by freely shaped dimensionalsurface is a surface structure which is not a conventional embossingprotrusion or embossing depression with a base surface, top surface anda fixed slope angle. Conventional elements are any embossing elementswhich are truncated cones or pyramids with polygonal or round or ovalbase areas, cylinders with polygonal or round or oval base areas, linearelements with fixed slope angle, elements with a base area which iscircular, elliptical, or a regular polygon with curved side surfaces.Such conventional embossing elements typically have a maximum extensionin the base plane not exceeding 4 millimeters. All such conventionalelements are not covered by the above term of a “freely shapedthree-dimensional surface”.

According to a preferred embodiment, at least one male protrusion orfemale depression has a lateral extension which exceeds 4 mm, preferablyexceeds 10 mm and most preferably exceeds 25 mm. In other words, thestructurized embossing surface of the inventive embossing roll has atleast one embossing element which has an extension exceeding that of aconventional element which usually has a maximum extension in the baseplane smaller than 4 mm.

Preferably the male protrusions or the female depressions are beingcharacterized by a height for the male protrusions or a depth for thefemale depressions of at least 0.4 mm, especially of at least 0.9 mm.The maximum height for the male protrusions and the maximum depth of thefemale depressions should not exceed 2.0 mm, especially 1.0 mm.

According to a preferred embodiment, at least one male protrusion orfemale depression has side walls with at least two different slopeangles between side wall sections and the adjacent base surfacesections. This serves as a further characteristic feature of theinventive embossing pattern on the embossing roll. Any conventions asregards shape, regularity including slope angles and overall shape ofthe embossing elements are left.

Preferably, at least one female depression is an elongate groove, thedepth of which continuously changes in at least a section of the groovein longitudinal direction of the groove. This again is a furthercharacteristic feature which contributes to a very high variety ofpossible geometries and shapes of the embossing elements of theinventive embossing roll. In addition to this, at least one femaledepression being an elongated groove can preferably have a width whichcontinuously changes in longitudinal direction of the groove in at leasta section of the groove. This characteristic feature, especially incombination with the above discussed changing depths of an elongategroove, leads to a very high variability of possible shapes of embossedprotrusions in the product which follows from the elongate depressionsin the inventive embossing roll.

According to a preferred embodiment, the embossing roll has at least twofemale depressions, the two female depressions having a different ratiobetween maximum depths in a radial direction, starting from the basecircumferential surface, and the opening area in the basecircumferential surface. To provide such differing opening ratiosfurther increases the options to provide recognizably differentgeometries for individual embossed protrusions. However, it should bementioned that there are technical constraints with regard to the freeselection of the opening ratio because, depending on the materialproperties of the fibrous product, the production device and the processconditions, the fibrous product to be processed will only be able toadopt the shape of such embossing protrusions or embossing depressionswhich it will be able to follow in shape. Nevertheless, a variation ofthe opening ratio opens a further possibilities towards a freelyselected three dimensions shape leaving standardized properties andgeometries of conventional embossing protrusions.

According to a further preferred embodiment of the invention, the rollhas at least one further base circumferential surface from whichselected male protrusions or female depressions start or at which theyterminate. In other words, the embossed geometries (male embossedprotrusions or female embossed depressions) need not necessarily startfrom the same base circumferential surface of the embossing roll.Instead, the freely shaped three-dimensional geometry might have e.g.large female depressions which are internally structured by intermediatesections of lower depths which subdivide one big female depression intoa plurality of individual sub-units. An example of such an inventiveembossing roll in which two different base planes might be defined willbe given below with reference to a preferred embodiment.

According to a preferred embodiment, at least one male protrusion is anelongate rib, the height of which continuously changes in at least asection of the rib in longitudinal direction of the rib.

According to a further preferred embodiment of the invention, at leastone male protrusion is an elongate rib, the width of which continuouslychanges in a longitudinal direction of the rib in at least a section ofthe rib. Both above characteristics, which can be realized separately orin combination in each male protrusion being an elongate rib, furtherserve to increase the variability of possible shapes and opticalappearances of the fibrous product embossed with such an embossing roll.

According to a preferred embodiment of the invention, selected anglesbetween side wall sections of male protrusions or female depressions andthe adjacent base circumferential surface exceed 30°. The use of a widevariety of such slope angles opens up the option to provide a highervariety of angles within either one single embossing element (maleprotrusion or female depression) or to provide more visible differencesbetween different embossing elements.

Preferably, the embossing roll is made of metal, especially steel, orhard plastics materials or hard rubber. In case of plastics, a very hardplastics material is preferred, alternatively a resin material is alsopossible.

Preferably, the embossing surface is formed by master-etching and/ormoletage processing. The masking process is often performed with a waxjet or with a laser partly ablating the mask. Such processing techniquesare able to lead to a high variety of surface geometries, wherein themoletage processing is mainly used in combination with an etchingtechnique which is applied where the metal after the moletage step wasdeformed most.

Alternatively, the embossing surface of the inventive embossing roll canalso be formed by mechanical machining, especially milling, which,however, can also be carried out in addition to masking etching and/ormoletage processing. With these production technologies at hand, it ispossible to freely shape the embossing surface of the embossing roll sothat the limits imposed to a free shape of the embossing roll is not thegeometry of the roll itself but the use of a shape which the inventivefibrous product still can substantially follow in the course of theembossing process.

A preferred embodiment of the inventive method for producing a multi-plyfibrous product is the bonding together the top ply and the further plyby means of a mechanical ply bonding. Such mechanical ply bonding which,for example, can be carried out by means of an edge embossing techniqueand/or by knurling, can either be carried out without the use of anadhesive or in additional to the application of adhesive. If amechanical ply bonding is used without adhesive, the resulting productcan retain a high degree of softness because the plies are onlyinterconnected where a mechanical ply bonding was carried out. In caseof a mechanical ply bonding in addition to laminating together the topply and the further ply by means of adhesive, any desired combination ofply bonding and a variation of the characteristic properties of themulti-ply product as influenced by adhesive bonding can be freelyselected.

For laminating together the single webs of material, different types ofadhesive can be used. Suitable adhesives are, inter alia, glue on thebasis of starch or modified starch like for example methyl cellulose orcarboxylized methyl cellulose and adhesively acting polymers on thebasis of synthetic resins, caoutchouc, polypropylene, polyisobutylene,polyurethane, polyacrylates, polyvinylacetat or polyvinyl alcohol. Suchadhesives can also contain dyes in order to improve the opticalappearance of the finished products. Frequently, water based glues areused for laminating together paper layers.

In a preferred embodiment of the method including laminating togetherthe top ply and the further ply by means of an adhesive, the adhesive issupplied to the protruding parts of the embossing roll. This techniquefor applying the adhesive can be used in combination with allpredominantly used manufacturing techniques like the Goffra Incolla-typeprocessing, a Pin-to-Pin lamination of two plies and a embossing devicein which two plies are combined using a Nested-method. In an attempt toinfluence the mechanical behaviour of the multi-ply fibrous product, theadhesive can be applied selectively on specific protrusions of theembossing roll. In other words, the adhesive is not applied to allprotrusions but only in selected sections of the embossing roll so thatthe overall ratio of the surface area in which adhesive has been appliedrelative to the overall surface area can be varied within a broad range.

According to a preferred embodiment of the inventive method, the methodfurther comprises the application of coloured adhesive or non-adhesivecoloured substances in order to apply colour to the top ply, preferablyon its side which is directed to the at least one further ply in afinished product. This method step further increases the highvariability of possible visual effects achieved in a multi-ply product.It is possible to freely combine the application of coloured substancesleading to a printed surfaces and/or the application of colouredadhesive to the three-dimensionally embossed ply. Preferably, suchcoloured substances are applied such that they are directed to theinside of a multi-ply product such that the coloured substances justshimmer through top and/or bottom ply to produce an optical appealingeffect.

According to a further preferred embodiment of the invention, theinventive method further comprises the step of pre-embossing the furtherply before directing it into the nip between the embossing roll and themarrying roll. Such pre-embossing step mainly serves to produce microprotrusions leading to a background pattern on the further ply of themulti-ply fibrous product. Micro embossing elements have a density ofmore than 20/cm², whereas embossing elements arranged in a density ofless than 20/cm² are defined herein as macro-protrusions.

As regards the temperature at which the process is carried out, it ispossible either to use room temperature or using heat embossing. The useof heat embossing technique serves to realize geometries which arecomplex, and therefore, difficult to realize for a given fibrous productespecially for non-woven products or hybrid products. In other words,the application of heat might be beneficial to realize highly complexembossing geometries in the inventive product. Further, heat embossingmay increase the stability of the embossed geometry.

Preferably, the embossing is carried out in the nip between theembossing roll and an anvil roll. However, according to an alternativepreferred embodiment, the embossing can also be performed using anultrasonic embossing technique.

According to a preferred embodiment of the invention, the top ply andthe at least one further ply a brought together in a Pin-to-Pinarrangement. In other words, the at least one further ply is alsoembossed using a similar or identical three-dimensional embossing rollsuch that embossed depressions of the top ply and the at least onefurther ply which contact each other can be laminated togetherPin-to-Pin. This implies that the embossing rolls for the top ply andthe at least one further ply are operated in register in order toproduce a well-defined and reproducible effect.

Alternatively, in a preferred embodiment of the method the top ply andleast one further ply are brought together such that they assume anested arrangement. This again makes it necessary that the embossingrolls for the top ply and the at least one further ply are operated inregister such as to realize a well defined nested arrangement of theplies once brought together.

According to a preferred embodiment of the inventive method, themulti-ply product has three plies wherein the top ply and the bottom plyare embossed using an inventive embossing roll, whereas the middle plyis volume embossed. The technique of volume embossing of conventionalproducts is known from WO2002/103112, the teaching of which isincorporated herein by reference. A volume embossed middle ply serves toimpart a high volume to the product and might be useful if a productwith the feeling of a high volume is desired.

The inventive device for producing fibrous products comprises aninventive embossing roll and a cooperating anvil roll. The anvil roll ispreferably made of rubber like EPDM or NBR (nitrylbutadien rubber),paper or steel.

According to a preferred embodiment of the invention, the anvil roll hasa hardness between 20 Shore A and 85 Shore A, preferably between 35Shore A and 60 Shore A and most preferably a hardness of about 45 ShoreA.

A preferred device comprises a pre-embossing device for the at least onefurther ply forming the backside ply. Such pre-embossing is carried outbefore the further ply is directed into the nip between the embossingroll and the marrying roll.

The device according to the invention can further comprise a deviceclose to the embossing roll for applying adhesive to the top ply. Suchdevice for applying adhesive is arranged such that the top ply beingprocessed can be arranged around the embossing roll and being in contactto a conventional device for applying adhesive to the side of the topply not being in contact with the embossing roll.

The device preferably comprises a marrying roll running against theembossing roll for bonding together the at least one top ply and atleast one further ply. Such marrying roll is used in the conventionalGoffra Incolla type process and for an embossing machine providing anested arrangement of two embossed plies. However, a marrying roll isnot necessary in case of a direct bonding together of two embossed pliesusing the above-described Pin-to-Pin ply bonding in which the tips ofthe embossing patterns of two plies face each other and are laminatedtogether at such tips. In such a case, the device preferably comprises afurther embossing roll running against the inventive embossing roll forembossing at least one further ply. This further embossing roll might bealso an inventive embossing roll. However, it is also possible to use aconventional embossing roll which applies conventional embossingelements to the backside ply such that in selected positions relative tothe inventive embossing roll processing the top ply, the tips of theembossing elements generated with both embossing rolls face each otherin order to achieve a Pin-to-Pin arrangement and bonding of the twoplies.

According to a preferred embodiment of the invention, the embossingpattern of the fibrous product, which can also be a single ply product,has the further characteristics that selected embossed protrusions orembossed depressions have a different ratio between height in adirection perpendicular to the base plane and the opening area in thebase plane. To provide such differing opening ratios further increasesthe options to provide recognizably different geometries for individualembossed elements (embossed protrusions or embossed depressions).However, there are technical constraints with regard to the freeselection of the opening ratios, because depending on the materialproperties of the paper product, the production device and the processconditions, the paper product will only be able to adopt the shape ofsuch embossing protrusions or embossing depressions which it is able tofollow in shape.

Preferably, the at least one ply of the fibrous product has at least onefurther base plane at which such selected embossed protrusions orembossed depressions extend from. In other words, the embossedgeometries need not necessarily start from the same base plane. Instead,the freely shaped three-dimensional geometry might have e.g. largeembossed protrusions which are internally structured by intermediatesections of lower heights which subdivide one big protrusion into aplurality of individual subunits.

Preferably, the fibrous product further comprises at least one furtherply forming the backside ply. Such backside ply might remain unembossedor, alternatively could have an embossing patterns as well or, as afurther alternative, have the same embossing pattern as the top ply. Thedefinition which of the plies is the top ply and which one is thebackside ply is arbitrary. However, for easier understanding, the atleast one ply with the three-dimensional embossing and being speciallyoptically appealing is considered to be the top ply of the fibrousproduct, whereas the at least one further ply forms a backside ply.However, it is possible that the top ply or top plies are embossedtogether in one nip and the backside ply or plies are also embossedtogether in another nip. Further, the product can also have one or moremiddle plies embossed separately from the top ply or plies and thebackside ply or plies.

In case that the backside ply is unembossed, such a product is easy tomanufacture because the unembossed backside ply can be directlytransferred to marrying unit where it is bonded to the top ply.

According to a preferred embodiment, the backside ply is embossed with asecond embossing pattern different to the embossing pattern of the topply, the second embossing pattern preferably comprising a microembossing pattern. A micro embossing pattern is a relatively regularpattern of densely arranged small embossed protrusions. A density ofembossed elements of more than 20/cm² is defined herein as a microembossing pattern. Such a micro embossing pattern can be selected freelybased on functional criteria in order to give the paper product certaincharacteristics in term of overall strength, bulk or smoothness. Opticalrequirements and effects do not play any decisive roll when selecting asuitable micro embossing pattern.

Preferably, the plurality of plies are adhesively bonded together,preferably using a coloured adhesive. The use of an adhesive is anothermeans to influence the technical properties of the combined product,especially the overall stiffness of the fibrous product. If colouredadhesives are used, this is selected in order to give a specific opticalappearance to the product. According to a preferred embodiment, thefraction of the surface area between the plies which is covered with anadhesive is more than 5% and less than 80%, preferably between 15% and60% especially between 20% and 50%. For standard multi-ply paperproducts with a nested arrangement of at least two embossed plies, thefraction of the surface area covered with adhesive is conventionallybetween 3% and 8%. From this comparison to conventionally used surfacearea fractions covered with adhesive, it follows that the inventiveproduct might have a much larger proportion of the overall area coveredwith adhesive. Such a high surface area which is preferably between 15%and 60% results in a stiff product which can be specially useful fornapkins.

In order to combine a plurality of plies and specially two pliestogether, the plies are preferably adhesively bonded together at thetips of the embossing patterns of the plies facing each other.

In another preferred embodiment of the invention, the multi-ply fibrousproduct comprises at least one middle ply which is volume embossed. Thetechnique of volume embossing of conventional products in known fromWO2002/103112 the teaching of which is incorporated herein by reference.A volume embossed middle ply serves to impart a high volume to theproduct and might be used if a product with the feeling of a high volumeis desired.

According to a preferred embodiment, the fibrous product comprises fourplies, at least one middle ply being embossed together with the adjacenttop ply.

According to a preferred embodiment of the invention, the top ply of afibrous product has an embodying pattern with embossed cushion-likeprotrusions whereas the bottom ply has embossed stabilizing elementswhich project into the cushion-like protrusions of the top ply. Such astructure has the advantage that relatively large dimensionedcushion-like protrusions can be provided which are stabilized by thestabilizing elements of the backside ply or bottom ply. For a moredetailed description of the concept of providing stabilizing elements,reference is made to WO2006/136186 the teaching of which is incorporatedherein by reference. The embossed stabilizing elements support thethree-dimensional structure of the top ply and avoid collapsing of thecushion-like protrusions.

Preferably, at least one ply of a multi-ply fibrous product has a colourwhich is different to the colour of the other ply or plies. Theprovision of a selected ply having a different base colour can furtherbe used to improve the optical appearance of multi-ply fibrous product.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 schematically shows a section of the circumferential surface ofan inventive, structurized embossing roll for producing the inventivepaper product;

FIG. 2 schematically shows a two ply inventive product, one of its pliesbeing embossed using the embossing roll as schematically shown in FIG.1;

FIG. 3 schematically shows the nip between two inventive, structurizedembossing rolls to be used in an embossing machine of the Pin-to-Pintype;

FIG. 4 shows a cross section of an example product using the embossingrolls as schematically shown in FIG. 3;

FIG. 5 schematically shows the nip between two inventive, structurizedembossing rolls to be used in an embossing machine of the Nested type;

FIG. 6 shows a cross section of an example product using the embossingrolls as schematically shown in FIG. 5;

FIG. 7 schematically shows a curved female depression in thecircumferential base surface of an embossing roll;

FIG. 8 shows an example of the production device and process of aninventive two ply product using an embossing machine of the GoffraIncolla type.

FIG. 9 a shows another example of a production device and process of aninventive two-ply product using an embossing machine of the Pin-to-Pintype;

FIG. 9 b shows a further example of a production device and process ofan inventive two-ply product using an embossing machine of thePin-to-Pin type and comprising an ink application device as well as anapplication device for adhesives.

FIG. 10 shows another example of a production device and process of aninventive two-ply product using an embossing machine of the Nested type;

FIG. 11 a is a schematic view of part of a conventional embossing rollwith single height male protrusions;

FIG. 11 b is a schematic view of a product embossed with a single heightembossing roll according to FIG. 11 a;

FIG. 12 a is a schematic view of a part of the circumferential surfaceof a conventional double height embossing roll; and

FIG. 12 b is a product embossed with a conventional double heightembossing roll according to FIG. 11 b.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a schematic view which shows only a small portion of thecircumferential portion of an embossing roll for producing the inventivepaper product. The embossing roll is preferably made of steel, very hardplastics, a resin or a hard rubber and is generally designated byreference numeral 10. In the specific embodiment as shown in FIG. 1, theembossing roll 10 has a female embossing geometry which means that,starting from a base circumferential surface 12 indicated by a dashedline, there are female depressions on the outer circumferential surfaceof the roll. Indicated by a double-dot-dashed line 14, a further basecircumferential surface 14 can be defined on the embossing roll. Besidesthe main depressions 16 extending from the base circumferential surface12, there are also further, smaller depressions 18 starting from thefurther circumferential base surface 14 and having a smaller depth thanthe main depressions 16.

From a comparison of the maximum depth D1 and D2 of two exemplarydepressions in the roll 10 it follows that the depressions might havedifferent depths. From the cross-sectional view as shown in FIG. 1, theextension of the depressions in a direction perpendicular to the planeof the drawing and within the base surface 12 cannot be judged. Sameapplies to the overall dimensions of the areas A as indicated exemplaryas A1 and A2 in FIG. 1. However, it is to be noted that the ratiobetween the depths D and the corresponding opening area A of a femaledepression can vary between the individual depressions 16, as well asbetween the individual depressions 18 starting from the second basecircumferential surface 14.

FIG. 1 also shows that the slope angles between parts of the side wallsections 17 of the depressions 16 and the direction perpendicular to thebase circumferential surface 12, i.e. the radial direction of the roll10 have different and freely selected values.

The exemplary surface pattern of the roll 10 can be obtained by anyknown method like machining, etching, masking-etching and moletage orsuitable combinations or these methods. The schematic view according toFIG. 1 intends to show that the embossing surface is of a freelyselected shape without constraints as regard a geometric similaritybetween different embossing depressions 16 or 18. The sizes, slopes ofthe side walls, definition of base circumferential surfaces and theareas of the openings at any such defined base surface can be freelyselected as long as the geometry allows the material to be embossed tosubstantially follow the shape of the embossing surface of the roll.

FIG. 2 shows a cross-sectional view of an inventive product 60,exemplified as a two-ply product consisting of a first ply 20 and asecond ply 30. The first ply 20 is the top ply and was produced usingthe inventive 3D-embossing technique using an embossing roll 10 as shownin FIG. 1. The second bottom ply 30 is provided with a micro-embossingpattern with a higher density of embossed geometries compared to the topply 20. Micro-embossing patterns have a density of the embossingelements exceeding 20/cm².

The top ply 20 is 3D-embossed forming embossed cushion-like protrusions22, whereas the micro-embossed protrusions of the backside ply 30 aredenoted with reference numeral 32. From the schematic drawing of FIG. 2it can be seen that several micro-embossed protrusions 32 extend intothe embossed cushion-like protrusions 22 of the top ply 20 and stabilizethem so that they support the cushion-like protrusions and avoid theircollapsing.

In the areas 40, the two plies are bonded together by means of adhesive42 which is locally applied to the base plane 24 of the first plycorresponding to the base circumferential surface 12 of the roll 10 asshown in FIG. 1.

In the top ply 20, a further base plane corresponding to the furtherbase surface 14 on the roll 10 can be defined which corresponds to thefurther base circumferential surface 14 of the roll 10 as shown in FIG.1 and subdivides the cushion-like protrusions into secondarycushion-like protrusions 41.

The second ply 30 is flattened by the marrying process in those areas inwhich the first ply 20 and the second ply 30 are adhesively bondedtogether. In order to increase the visual effect, the adhesive 42 can becoloured.

FIG. 3 schematically shows the nip 11 between two inventive,structurized embossing rolls 10 a and 10 b to be used in an embossingmachine and process of the Pin-to-Pin type. To this end, the two3D-embossing rolls 10 a and 10 b have a surface topography which is amirror image of each other. In fact, in order to achieve an arrangementof two plies in the Pin-to-Pin mode, it is not necessary that theembossing surface of the two cooperating embossing rolls is identical interms of a mirror image. It is sufficient that selected raised portionsin the embossing geometry of the two cooperating rolls face each other.In the example shown in FIG. 3, both rolls 10 a and 10 b are providedwith female depressions 16, but there can be defined some additionalcircumferential surfaces 14 as well as 15 defining additional surfacesand forming the starting point for further female depressions 18 and 19extending from planes 14 and 15, respectively. The nip, i.e. distancebetween the two base circumferential planes 12 a, 12 b is adjustedaccording to the thickness of the fibrous product processed and possibleadditional layers forming one or more middle plies.

FIG. 4 shows an example of a multi-ply product formed by means of thepair of rolls as schematically shown in FIG. 3. The first ply 20 and thesecond ply 30 follow the shape of the embossing rolls 10 a, 10 b, theabove described loss between the geometry of the embossing roll and thegeometry of the embossed fibrous product not being considered here. Sucha loss results in a slightly reduced height of the embossing elementswithin the resembling product compared with the heights of the embossingelements at the embossing roll. As can be seen, there is a third ply 21which is volume embossed. Volume embossed means that the third ply 21receives an irregular embossing pattern which is not in register to theembossing pattern of the first ply 20 and second ply 30. The effect ofthe volume embossed middle ply 20 is to stabilize the embossedprotrusions 22 of the first and second plies 20, 30. A product as shownin FIG. 4 is manufactured by separately volume embossing the middle ply21 and then directing the middle ply into the nip 11 between theembossing rolls 10 a and 10 b as shown in FIG. 3. In the nip 11 betweenthose parts of the embossing rolls lying in the base circumferentialplanes 12 a, 12 b and facing each other, the three plies are ply bondedtogether using an adhesive applied to ply 20 and/or ply 30 in the courseof their individual embossing steps but before being directed into thenip 11 between the two embossing rolls as shown in FIG. 3.

As an alternative to the arrangement of embossing rolls and the productas shown in FIGS. 3 and 4, there might be more than one volume embossedmiddle ply or a middle ply which is not embossed. Further, the geometryof the two embossing rolls 10 a, 10 b might be different, the embossingsurface of both rolls not being a mirror image to each other. This ispossible as long as the two rolls are operated in a coordinated mannerand there are well defined portions of both rolls in which ply bondingis generated in the nip 11 between both embossing rolls 10 a, 10 b.

The embodiment according to FIG. 5 and the product resulting therefromas shown in FIG. 6 are different in that two embossing rolls 10 a, 10 care used which have a different shape and are arranged such that theplies embossed separately on rolls 10 a and 10 c can be combinedtogether in a further process step to achieve a nested arrangement ofthe plies.

Embossing roll 10 a is identical to embossing roll 10 a according toFIG. 3 so that for any further explanations reference can be made to thedescription of FIG. 3. The embossing roll 10 c is provided with discreteprotrusions 23 which can have either an identical shape or a differentshape as in the example of embossing roll 10 c in which there is adifference between different types of protrusions 23 a, 23 b and 23 c .. . . The process using the embossing rolls 10 a and 10 c will bedescribed later with reference to FIG. 10.

When combining together two plies 20 and 30 as produced separately onthe embossing rolls 10 a, 10 c and combining together the two plies 20and 30 between the first embossing roll 10 a and the marrying roll, aproduct as schematically shown in FIG. 6 is obtained. The bottom ply 30is provided with protrusions 33 which project into the embossedprotrusions 22 of the first ply 20 and provide a stabilizing effect ofthe protrusions 22 of first ply 20. This is advantageous because,embossing roll 10 a according to the invention provides a freelydesigned three-dimensional surface so that complex shapes and large sizeembossed depressions or embossed protrusions might be formed which keeptheir shape in a more stable way if the bottom ply is provided withsupport embossments 33 as schematically indicated in FIG. 6.

FIG. 7 schematically shows another characteristics of the inventiveembossing roll. It shows a small section of the base circumferentialsurface of a roll 10 with a female depression 16 formed therein. Thefemale depression has curved side walls in the cross-sectional view asshown in FIG. 7. What is meant by curved side walls are not only smallrounded sections in the transition between the base circumferentialsurface and conventional embossing depressions but a curvature which mayextend over a considerable part of or all over the sidewalls. In FIG. 7there are shown two fictitious orthogonal lines starting from the curvedsurface of the female depression. Both orthogonal lines cross the basecircumferential surface in an angle indicated by β₁ and β₂ which isdefined as the smallest angle which exists between the orthogonaldirections O₁ and O₂ and the base circumferential surface 12 of theembossing roll 10. It can be seen that two orthogonal directions can bedefined both of which start from selected positions of the curved localsurface of the female depression such that the two orthogonal directionscross the base circumferential surface at angles satisfying the equation30°<|β₁−β₂|<90° and preferably 50°<|β₁−β₂|<90°. Here, it should be notedthat the angles β₁ and β₂ have a different direction leading to adifferent mathematical algebraic sign.

FIG. 8 shows a first embodiment for providing a two-ply productaccording to the invention using the Goffra Incolla technology. In theexample as shown in FIG. 8, the first ply 20 is 3D-embossed between ananvil roll 50 and an inventive embossing roll 10 as exemplified inFIG. 1. Adhesive is applied to the base surface 12 of the threedimensional embossing roll 10 (if the three dimensional embossing rollis provided with female depressions as shown in FIG. 1) or is applied tothe top surfaces of male embossing protrusions, if the 3D-roll has maleprojections on its circumferential surface. Adhesive is applied by meansof an application device 52 comprising an application roll 53. Thesecond ply 30 can be optionally pre-embossed between a micro-embossingroll 54 and a corresponding anvil roll 56 and is subsequently fed to themarrying station between the three dimensional embossing roll 10 and amarrying roll 58 as is conventionally used in the art. The two-plylaminated product 60 corresponding to that as shown in FIG. 2 leaves theschematic device as shown in FIG. 8.

An alternative embossing device and method in the Pin-to-Pin type isschematically shown in FIG. 9 a. The first ply 20 is three dimensionallyembossed between the inventive 3D-embossing roll 10 and the anvil roll50 and an adhesive is applied by an application device 52 comprising anapplication roll 53. The second ply 30 is also provided with a threedimensional embossing pattern between a further inventive 3D-embossingroll 62 and a corresponding anvil roll 64. The second three dimensionalembossing roll can be of the same type as roll 10, i.e. both rolls canbe provided with male protrusions and/or female depressions or can be ofthe other type so that one of the rolls 10, 62 has female depressionsand the other roll has male protrusions. The two plies 20 and 30 arecombined together in the nip between the two embossing rolls 10 and 62leading to a two-ply laminated product 60. The type of embossing deviceand method as shown in FIG. 9 a can be of the type as shown in FIG. 3above.

FIG. 9 b shows an embossing device and a method of the Pin-to-Pin typeidentical with FIG. 9 a with the exception that the adhesive applicationdevice 52 is connected with 3D-embossing roll 62 instead of roll 10 andthat an additional color (ink) application device 72 is connected with3D-embossing roll 10.

FIG. 10 shows a further alternative embossing device and method of theNested type. The first ply 20 is three-dimensionally embossed betweenthe inventive 3D-embossing roll 10 and the anvil roll 50 and an adhesiveis applied by conventional applicator device 52 comprising anapplication roll 53. The processing of the first ply 20, therefore, isidentical to that as described above with reference to FIGS. 8, 9 a and9 b. At least one further ply 30 is provided with an embossing patternbetween an embossing roll 63 which can either be an inventive3D-embossing roll or a conventional embossing roll. The second ply 30 isembossed between roll 63 and anvil roll 64 before it is directed intothe nip between the 3D-embossing roll 10 for the first ply and amarrying roll 58 cooperating with the 3D-embossing roll 10 for the firstply. Embossing rolls 10 and 63 are operated in register so that a nestedarrangement as schematically shown in FIG. 6 can be realized. Theembossing roll 63 for the at least one further ply 30 can be of the typeas exemplified by the embossing roll 10 c in FIG. 5, but any othergeometry leading to a nested arrangement of the embossed elements of thesecond ply 30 in the embossed elements of the first ply 20 is possibleto achieve the desired result.

The inventive embossing roll in combination with the three dimensionalembossing method and device makes it possible to produce fibrousproducts which have a much higher versatility of embossing patternscompared to conventional fibrous products. There are nearly no moreconstraints as regards the geometry of individual embossing patternsexcept the need for a suitable fibrous product to follow the shape ofthe 3D-embossing rolls in the course of the production method.

1-58. (canceled)
 59. Embossing roll for producing fibrous productsselected from the group consisting of tissue paper products, non-wovenproducts or a hybrid thereof, and hygiene and cleaning products, with astructurized embossing surface suitable to run against an anvil roll,the structurized embossing surface comprising male protrusions or femaledepressions starting from a base circumferential surface of the roll;the embossing pattern being characterized by the following features: thebase areas of selected male protrusions or female depressions in thebase circumferential surface are different; the heights or depths ofselected male protrusions or selected female depressions in a radialdirection of the roll and starting from the base circumferential surfaceare different; the angles between sidewall sections and the adjacentbase circumferential surface of selected male protrusions and/or femaledepressions are different; at least one male protrusion or femaledepression has sidewalls with at least two different slope anglesbetween sidewall sections and the adjacent base surface; and selectedangles between side wall sections of male protrusions or femaledepressions and the adjacent base surface exceed 30°.
 60. The embossingroll according to claim 59, which is characterized by angles β₁, β₂being defined as the crossing of the orthogonal directions starting fromselected positions on the local surface of male protrusions and/orfemale depressions and the base circumferential surface, wherein suchangles β₁, β₂ are greater than 30°, or smaller than 20°.
 61. Theembossing roll according to claim 59, wherein the local surface of atleast one female depression is curved such that two orthogonaldirections starting from selected positions on the local surface can bedefined, the two orthogonal directions crossing the base circumferentialsurface at angles β₁, β₂ satisfying the equation 30°<|β₁−β₂|<90°. 62.The embossing roll according to claim 59, wherein the structurizedembossing surface is a freely shaped three-dimensional surface.
 63. Theembossing roll according to claim 59, wherein at least one maleprotrusion or female depression has a lateral extension which exceeds 4mm, whereby the male protrusions are characterized by a minimum heightof 0.4 mm and a maximum height of 2.0 mm and whereby the femaleprotrusions are characterized by a minimum depth of 0.4 mm and a maximumdepth of 2.0 mm.
 64. The embossing roll according to claim 59, with atleast one female depression which is an elongated groove, the depths ofwhich continuously changes in at least a section of the groove inlongitudinal direction of the groove, or the width of which continuouslychanges in longitudinal direction of the groove in at least a section ofthe groove.
 65. The embossing roll according to claim 59, with at leastone male protrusion which is an elongate rib, the height of whichcontinuously changes in at least a section of the rib in longitudinaldirection of the rib or the width of which continuously changes inlongitudinal direction of the rib in at least a section of the rib. 66.The embossing roll according to claim 59, with at least two femaledepressions, the two female depressions having a different ratio betweenmaximum depths in a radial direction starting from the basecircumferential surface and the opening areas in the basecircumferential surface.
 67. The embossing roll according to claim 59,having at least one further base circumferential surface from whichselected male protrusions or female depressions start.
 68. The embossingroll according to claim 59, wherein the embossing surface is formed bymasking-etching and/or moletage processing and/or mechanical machining.69. Method for producing a multi-ply fibrous product, selected from thegroup consisting of a tissue paper product, non-woven product or ahybrid thereof and a hygiene and cleaning product, comprising thefollowing steps: (a) embossing a top ply using an embossing rollaccording to claim 59; (b) supplying at least one further ply suchfurther ply optionally being pre-embossed before being directed into anip between an embossing roll and a marrying roll; (c) bonding togetherthe top ply and the further ply in the nip between the embossing rolland a marrying roll or in the nip between the embossing roll and asecond embossing roll for embossing the further ply.
 70. The methodaccording to claim 69, wherein in step (c) the bonding is carried out bya mechanical ply bonding or by laminating together the top ply and thefurther ply by an adhesive.
 71. The method according to claim 70,wherein the adhesive is applied towards the protruding parts of theembossing roll, especially selective towards specific protrusions of theembossed roll.
 72. The method according to claim 69, further comprisingthe application of coloured adhesive and/or non-adhesive colouredsubstances in order to apply colour to the top ply, on a side which isdirected to the at least one further ply in the finished product. 73.The method according to claim 69, wherein the embossing in step (a) isperformed using an ultrasonic embossing technique in the nip between theembossing roll and an anvil roll.
 74. The method according to claim 69,wherein the top ply and the at least one further ply are broughttogether in a Pin-to-Pin arrangement or in a nested arrangement.
 75. Themethod according to claim 69, wherein the multi-ply product has three orfour plies; the bottom ply being embossed using the embossing roll; atleast one middle ply is volume embossed wherein the middle ply isembossed together with the top ply.
 76. Device for producing fibrousproducts with at least one top ply, selected from the group consistingof tissue paper products, non-woven products or a hybrid thereof, andhygiene and cleaning products, comprising: an embossing roll accordingto claim 59; and a cooperating anvil roll; and optionally apre-embossing device for at least one further ply.
 77. The deviceaccording to claim 76, further comprising an application device arrangednext to the embossing roll for applying adhesive to the top ply wherebysuch application device comprises an application roll for applyingadhesives whereby such an application roll is a structured applicationroll.
 78. The device according to claim 76, further comprising amarrying roll running against the embossing roll for bonding togetherthe at least one top ply and at least one further ply.
 79. The deviceaccording to claim 76, further comprising a further embossing rollrunning against the embossing roll for embossing the at least onefurther ply.
 80. The device according to claim 76, further comprising:an additional embossing roll running against the first embossing rollfor embossing at least one additional ply; a device for applyingadhesives either to the top ply or to the bottom ply whereby the devicefor applying adhesives comprise an application roll; and a device forapplying colour either to top ply or to bottom ply.
 81. Fibrous productselected from the group consisting of tissue paper product, non-wovenproduct or a hybrid thereof, and hygiene and cleaning product, with atleast one ply with an embossing pattern comprising embossed depressions,or embossed protrusions, the embossed depressions or embossedprotrusions starting from a base plane of the ply; the embossing patternbeing characterized by the following features: the base areas ofselected embossed depressions or embossed protrusions, in the base planeare different; the depths of selected embossed depressions or theheights of selected embossed protrusions perpendicular to the base planeare different; the angles between sidewall sections and the adjacentbase plane of selected embossed depressions or embossed protrusions aredifferent; at least one male protrusion or female depression havesidewalls with at least two different slope angles between sidewallsections and the adjacent base surface; and selected angles between sidewall sections of male protrusions or female depressions and the adjacentbase surface exceed 30°.
 82. The fibrous product according to claim 81,wherein the embossing pattern has the following characteristics:selected embossed protrusions or embossed depressions have a differentratio between height or depth in a direction perpendicular to the baseplane and the opening area in the base plane.
 83. The fibrous productaccording to claim 81, wherein the at least one ply has at least onefurther base plane at which selected embossed protrusions or embosseddepressions extend therefrom.
 84. The fibrous product according to claim81, further comprising at least one further ply forming the backside plywherein the backside ply may be unembossed or wherein the backside plyeither has the same embossing pattern as the top ply or is embossed witha second embossing pattern different to the embossing pattern of the topply, the second embossing pattern comprising a micro embossing pattern.85. The fibrous product according to claim 81, wherein the plurality ofplies are adhesively bonded together using a coloured adhesive wherebythe fraction of the surface area covered with adhesives between theplies is more than 5% and less than 80%, wherein the plurality of pliesare optionally adhesively bonded together at the tips of the embossedpatterns of the plies facing each other and wherein the plies are onlypartly bonded together.
 86. The fibrous product according to claim 82,wherein the top ply has an embossing pattern with embossed cushion-likeprotrusions; and the bottom ply has embossed stabilizing elements whichproject into the cushion-like protrusions of the top ply.